Evid Based Nurs 9:46 doi:10.1136/ebn.9.2.46
  • Treatment

Review: dietary intervention plus exercise is no better than dietary intervention alone for inducing long term weight loss

 Q In overweight and obese adults, is a combination of dietary intervention and exercise more effective than dietary intervention alone for inducing long term weight loss?


GraphicData sources:

Cochrane Controlled Trials Register (Cochrane Library), Medline, and LILACS (all up to March 2003). Published reviews and all relevant studies and their reference lists were also scrutinised for other pertinent publications.

GraphicStudy selection and assessment:

randomised controlled trials (RCTs) published in any language that compared a combination of dietary intervention (including any type of caloric restriction) and exercise (any type of exercise in which it was possible to quantify the recommended activity) with dietary intervention alone in overweight or obese adults (body mass index >25 kg/m2). RCTs were also required to have ⩾1 year of follow up. Study exclusion criteria included enrolment of pregnant women, use of any medication, and use of behavioural therapy as the only intervention. Individual study quality was assessed using criteria adapted from the Jadad scale or the Delphi list.


weight loss immediately after intervention and at 1 year of follow up.


6 RCTs (n = 407) (age range 21–65 y) met the selection criteria. Duration of interventions ranged from 10 to 52 weeks, and follow up ranged from 12 to 24 months. Meta-analysis was done using a fixed effects model. The groups did not differ for weight loss (table).


In overweight and obese adults, a combination of dietary intervention and exercise is not better than dietary intervention alone for inducing long term weight loss.

See commentary next page.


  1. Colleen Keller, RN, CS, FNP, PhD
  1. College of Nursing, Arizona State University, Tempe, Arizona, USA

      Obesity and concomitant cardiovascular risks, type 2 diabetes, hypertension, and hyperlipidaemia have reached epidemic proportions.1 Clinicians need evidence and guidelines on successful strategies to counsel patients on long term weight loss. The review by Douketis et al showed very small weight loss with diet and lifestyle treatment and modest to large long term weight loss with pharmacological and surgical treatment, accompanied by reductions in cardiovascular risk factors in high risk groups only. Clinical applicability is limited by the use of low or very low calorie restricted diets, including pre-packaged foods; lack of detail regarding behavioural counselling; and either lack of measurement of exercise levels or lack of restriction of exercise to the treatment group. It was difficult to assess the unique effects of caloric restriction, exercise, or the elements of behavioural counselling as they were bundled together. Of course, such combinations are often used by dieters within or outside of formal programmes.

      The review by Curioni and Lourenco concluded that dietary intervention plus exercise results in statistically significant and clinically meaningful initial weight loss compared with dietary intervention alone. However, p values and confidence intervals were not within conventional values of statistical significance.

      These 2 reviews show that primary research on weight loss continues to be hampered by methodological issues of high drop out rates, where the results are based on completers only or last observation carried forward and overestimate treatment effect; lack of attention to high risk groups; lack of appropriate comparison groups; and need for longer follow up.

      Although both reviews described the strategies used to effect weight change, neither considered the mechanisms of the interventions reviewed. Theory based interventions have been shown to contribute significantly to success in weight management and physical activity.2

      We are left with patients needing to reduce weight to reduce health risks but little evidence to support many specific interventions. Clinicians who suggest weight loss or weight maintenance strategies need to take into account individual patient preferences and situations and to help them plan methods of dietary practices and food preparation to encourage healthy eating, along with planned physical activity. Although the review by Douketis et al showed the effectiveness of pharmacological and surgical interventions, these approaches should be recommended only after careful consideration of harms and benefits, particularly in light of the limited information on cardiovascular risk factor reduction and cardiac event follow up.


      Dietary intervention plus exercise v dietary intervention alone in overweight and obese adults*

 Q In overweight and obese adults, is a combination of dietary intervention and exercise more effective than dietary intervention alone for inducing long term weight loss?


      • For correspondence: Dr C C Curioni, Instituto de Medicina Social, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil. c_curioni{at}

      • Source of funding: not stated.

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